DE 1 650 206 A discloses a generic piston for an internal combustion engine having pin bores for accommodating a piston pin, the pin bores being formed in a transversely oval manner to the longitudinal axis of the piston for load optimisation. The transversely oval formation of the pin bores is intended in particular to ensure reliable oil supply during operation of the internal combustion engine. The transversely oval pin bore should also have a noise-damping effect and be able to absorb the different thermal expansions of the piston and of the pin.
U.S. Pat. No. 2,990,226 also discloses a generic piston having a transversely oval pin bore.
DE 36 09 019 C1 discloses a method for producing a pin bore of a trunk piston, in which pocket-like recesses are formed in the pin bores, starting from the piston interior, to avoid boss cracks. With pistons in which the connecting rod is guided through the boss of the piston in the direction of the crankshaft longitudinal axis, lubricating oil is introduced into the said pockets from the connecting rod small end. In order to be able to guide the latter to the radially outer end of the pin bore with the least possible reduction in the pin bore area, even with pockets formed in the pin bore, a groove that leads radially outwards and acts as an oil channel is formed on the pockets during cutting with the aid of a change in the position of a milling tool cutting the pockets. However, a second work step is needed to form the said groove.
US 2007/0095200 A1 likewise discloses a generic piston having a transversely oval pin bore, the pockets mentioned in the said document likewise having to be produced in a separate work step.